Biomarkers in critical care nutrition

Abstract

The goal of nutrition support is to provide the substrates required to match the bioenergetic needs of the patient and promote the net synthesis of macromolecules required for the preservation of lean mass, organ function, and immunity. Contemporary observational studies have exposed the pervasive undernutrition of critically ill patients and its association with adverse clinical outcomes. The intuitive hypothesis is that optimization of nutrition delivery should improve ICU clinical outcomes. It is therefore surprising that multiple large randomized controlled trials have failed to demonstrate the clinical benefit of restoring or maximizing nutrient intake. This may be in part due to the absence of biological markers that identify patients who are most likely to benefit from nutrition interventions and that monitor the effects of nutrition support. Here, we discuss the need for practical risk stratification tools in critical care nutrition, a proposed rationale for targeted biomarker development, and potential approaches that can be adopted for biomarker identification and validation in the field.

A guide to enteral nutrition in intensive care units: 10 expert tips for the daily practice

“…IC-guided nutrition therapy, however, did not convincingly improve outcomes, in the absence of methodologically sound evidence [ 44 – 47 ]. The individualization of feeding based on a biomarker is not yet validated [ 48 , 49 ].…”

“…Patients in shock receiving early full EN compared to PN more often developed Ogilvie’s syndrome and bowel ischemia [ 22 ]. Monitoring and management of EFI and GI dysfunction is complicated due to the lack of robust and reproducible markers and multifaceted clinical presentation [ 49 ]. As no single straightforward marker reliably detects GI dysfunction, using composite scores combining several symptoms and signs could be helpful and should be considered [ 131 ].…”

Nutrition Care Process of Surgical Patients in the Context of Enhanced Recovery After Surgery

“…Patients' nutritional status should be determined before surgery. Biochemical and anthropometric measures have low sensitivity and specificity, and baseline clinical parameters such as BMI, whole-body protein balance and nitrogen balance, insulin resistance, albumin, prealbumin, body composition, and markers of inflammation (interleukin-6 and C-reactive protein) best reflected metabolic responses to nutrition 46–48 …”

Trial Design in Critical Care Nutrition: The Past, Present and Future

“…Future critical care nutrition research is likely to place a greater focus on specific clinical populations, with greater consideration of individual patient characteristics to enable personalised or individualised therapy and to account for factors such as pre-morbid nutrition status, body composition, and stage of disease. A minimum common dataset of patient population characteristics to be reported may support the advancement of this, as too may the use of metabolic biomarkers to determine those patients most likely to benefit from nutrition support [68,69]. Though nutrition risk scores have been developed, they have been poorly validated, are often inaccurate, and may reflect injury severity more than nutrition risk [70], which may reduce the number of patients needing to receive the intervention in order to see benefit.…”